Pellet mill parts

pellet mill die

pellet mill die

pellet mill roller

pellet mill roller

pellet mill shaft and couplings

pellet mill shaft and couplings

Pellet mill parts introduction

The wood pellet machine is composed of several parts such as pellet mill dies, rollers, roller shells, bearings, gearboxes, shaft, screw feeders, etc. Stable operation can be achieved through the assembly of each component. Let’s take a closer look at the wood pellet machine’s accessories and wear parts below.

Ring die for ring die pellet mill

Among the ring die pellet machines, stainless steel ring dies are the most used dies and require special gun drills and vacuum heat treatment equipment to produce high quality ring dies. The excellent high temperature vacuum quenching process can significantly improve the rigidity, hardness, abrasion resistance, fatigue strength and toughness of steel.

Stainless steel materials include German stainless steel X46Cr13, Chinese stainless steel 4Cr13, etc. These materials have good stiffness and toughness, a higher heat treatment hardness than carburized steel, a harderened layer than carburized steel, and good wear and corrosion resistance, so they have a longer life and are naturally more expensive than carburized steel. Due to the long life of the stainless steel die steel, the replacement frequency is low, so the tonnage/consumption cost is low.

Flat die for flat die pellet mill

The flat die pellet machine has two or three rollers and the diameter of the hole is generally 2.5-16 mm. Compared to the ring die, the flat die design is relatively simple and compact. Generally, the flat dies are made of various metal materials to ensure the corrosion resistance of the moulds. Alloy structural steel, such as 40Cr, 35CrMo, etc., heat treatment hardness is above 50HRC, and has good integrated mechanical properties. The flat die made of this material has high strength and wear resistance.

Pellet mill roller

In a pelletizer, the rollers are the second most important  pellet mill parts. 2 or 3 rollers are connected together by a roller shaft. Pellet mill rollers are cylindrical bodies with a variety of surfaces, the main function of the rollers is to help the material mixture enter the die hole, therefore the shape and structure of the rollers are designed to prevent the material from slipping and make its surface smooth for better discharge.

 When working, the roller shaft rotates around the spindle and the pellet mill roller rotates around the spindle at the same time. The diameter of the roll varies with the size of the production.

The hardness of the roll is lower than that of the pellet mill die, which reduces wear on the flat die and extends its working life. All rollers should have the same clearance to the pellet mill  die to achieve uniform pressure. The clearance is between 0.1 and 0.3mm.

The rollers are tapered to ensure the same speed at both ends. This design prevents rollers from slipping, reduces energy waste and reduces wear on flat moulds. In addition, it employs a spiral pressure regulator. The gap between the rollers and the mold can be adjusted to suit different materials to ensure molding results.

Pellet mill roller shell

Multiple roller shells are used in turn to keep the working surface of the ring die flat
The flatter the working surface of the ring die, the flatter the roller shell, the higher the capacity and life of the ring die and rollers, and the more stable the particle quality.
The ring die is already in its late stages and the old roller shells can be used when the working surface is not flat enough to make full use of both without waste!
Don’t use the shell when it is very smooth before scrapping it, it will only increase the power consumption.


The main causes of bearing damage in pellet machine: ① material fatigue; ② poor lubrication; ③ contamination; ④ installation problems; ⑤ improper handling.

The bearing is usually used under normal conditions, but not all the traces indicate that the bearing is broken.

But bearing damage in any part of the pellet machine is largely due to material fatigue in a third of the cases; poor lubrication in a third; and improper handling of contaminants into the bearing or installation.

The basic function of the bearing is to reduce mechanical friction and ensure more efficient and smooth operation of the pellet machine. Our high quality NSK bearings, manufactured in Japan, help reduce energy consumption, high efficiency and low noise for stable operation.

Pellet mill knives

The pellet cutting knives are all made of stainless steel with an oil seal to prevent oil from entering, eliminating corrosion and making adjustments easy. The main function of a pelletizer is to cut the wood pellets to a certain size as needed.

Pellet mill safety pins

Pellet machine safety pins play a protective role in the operation of the pellet machine,prevent damage to the die and spindle of the pellet machine after overload.

PALET has an ample stock of quality wood pellet accessories to ensure that customers’ emergency needs are met with timely delivery. Please feel free to contact us if you have any needs, we are happy to provide you with quality products and first-class service.